This invention relates to a device for calculating an amount of money or charge which a subscriber should pay for reception of a pay television signal or a like information signal.
The invention will be described in connection with a pay television network, which may be either of the broadcast type or of the closed-circuit type. In a pay television network, television programs are available only for those subscribers who have either paid a charge or fare or are willing to pay. There are two basic methods by which fees are collected. According to one method, the subscriber preliminarily subscribes to the programs which he wants to receive or watch. The other method makes use of the per program or per view billing technique. According to this method, the receiver for the pay television signal is accompanied by a charging device. In either case, the subscriber may deposit a credit in advance or pay the fare upon reception of a bill from the dealer of the pay television network. As will be understood as the description proceeds, the charging device is also useful when a subscriber preliminarily subscribes to some programs but subsequently wishes to receive a program for which subscription was not booked in advance.
The charging device displays or otherwise produces an indication of the amount of charge or fare which should either be paid or subtracted from the subscriber's credit for programs actually received at certain time instants. The subscriber reports to the dealer the amount of charge at the end of each billing period as, for example, monthly. An error may occur in the report to the dealer if the subscriber erroneously reads the display of the charge or incorrectly writes down the amount. In an extreme case, a deceitful subscriber might intentionally report only a small charge despite the display.
According to the tiering method of subscriber billing, programs are classified into tiers or categories. Codes or parameters are assigned to the respective tiers. The television signal is transmitted after being encoded or scrambled by respective codes. When the per view billing technique is applied to a tiered television network, cost information for the respective tiers must be transmitted on the television signal. This requires an additional frequency band.